Cloth guider



June 17, 1947. J. D. ROBERTSON CLOTH GUIDER Filed Sept. 50, 1944 3 Sheets-Sheet 1 IN VEN TOR.

June 17, 1947. J. D. ROBERTSON 2,422,369

CLOTH GUIDER Filed Sept. 50, 1944 5 Sheets-Sheet 2 Patente d June 17, 1947 CLOTH GUIDER John D. Robertson, Taunton,

Mount Hope Machinery Company,

Mass, 'assignor to Taunton,

Mass., a corporation of Massachusetts Application September 30, 1944, Serial No. 556,573

18 Claims.

This invention relates to improvements in cloth guiders and more particularly to that class of cloth guiders which are self-acting to correct selvage deviations, as distinguished from the relatively more complicated and more expensive cloth guiders which require the intervention of an exterior power medium, such as electricity, compressed air, and the like, for controlling the selvage correcting means.

. Cloth guiders of the general type to which the invention relates ordinarily have tiltable pairs of rolls which engage opposite selvage regions of a' travelling web of cloth, and each pair of rolls is responsive automatically to change the degree of tilt of the rolls whenever the engaged selvage region of the web departs from a predetermined transverse relationship to the center-line of travel of the web. The respective pairs of rolls are separately tiltable in parallelism with the plane of the Web engaged thereby so that a transverse traction or repulsion can be exerted by the rolls on the cloth which traction or repul sion is varied by increase or decrwse of the angle of tilt of the rolls relative to a plane at right angles to the plane of the traveling web.

It is an object of my present invention to utilize the tilting roll principle of prior disclosures but to provide means whereby the variations in the tilt of the rolls are more sensitively responsive to selvage deviations, as compared with the prior disclosures. I provide sectional rolls and means sensitively responsive to selvage deviations for braking one or more roll sections when a selvage is out of its predetermined line of travel, thereby to impose a drag on the web on that side of the pivot of the rolls which will cause tilting thereof in direction to effect a lateral shifting of the selvage into its predetermined line of travel.

Another object is to provide a pivotally mounted pair of web-engaging rolls which constantly are acted upon by two oppositely directed forces which tend to tilt the pair of rolls as a unit in opposite directions about their pivot, at least one of said forces being adjustable for setting the roll unit, when free of a web, in a state of balance with the roll axes in a predetermined selective plane.

Another object of my invention is to provide an efficient cloth guide which can be lighter in weight and simpler in construction than the prior .cloth guiders.

A further object is to provide an improved guider roll structure suitable for coacting with my'improved selvage-actuated braking features.

An additional object is to provide means for readily and effectively adjusting the braking means to compensate for wear.

It is, moreover, my purpose and Object generally to improve the structure and operation of self-acting cloth guides.

In the accompanying drawings:

Figure 1 is a top plan view of a tiltable cloth guide mechanism embodying features of my invention, between whose rolls one selvage region of a web of cloth is shown in cross-section, it being understood that a similar mechanism will engage the opposite selvage region of the web;

Figure 2. is a cross-sectional view on line 2-2 of Figure 1;

Figure 3 is a side elevation of the mechanism of Figure 1 with the near roll removed and its brack t broken away, the central portion of the rear roll also being broken away;

Figure 4 is a cross-sectional view on line 4-4 of Figure 1;

Figure 5 is a front elevation showing my im-' proved cloth guiding units engaging opposite selvage regions of a web of cloth; and

Figure 6 is a fragmentary front elevation of a modified form having selvage engaging fingers on the brake -actuating lever.

Referring to the drawings, the cloth guiding mechanisms, one at each selvage region of the web W of cloth as seen in Fig. 5, are designed to serve respectively at the right and left sides of the machine but otherwise will be substantially the same in structure and operation, and a detailed description of one mechanism will be equally applicable to the other.

Referring to Fig. 1, each mechanism comprises a pair of rolls indicated generally at l0 and i2 carried on a swinging arm 14 whose pivotal axis I6 is on a base l8 which is adapted for securement to a member 20 (Fig. 5) which is adjustable on the bar 22 extending from side to side of the web W. The rolls l0, [2 are illustrated in an arrangement for co-action with a web W which travels downward in a vertical plane although obviously the web might travel upward or may approach the guide rolls in a horizontal plane or in any inclined plane between vertical and horizontal, in each of which cases the guiding mechanism and coacting elements would be correspondingly shifted for effective co-action with the web.

In the embodiment herein represented, the axis N5 of the roll-carrying arm I4 is at right angles to the plane of travel of the web to the rolls,-

and'is located in rear of the rolls at a mid-locais rocked about its pivot 56'.

tion along their extent and in the horizontal plane of the axis of the rolls. Arm [4 extends from its axis in general direction parallel with the plane of the web W at the rear side of the latter and, at a location beyond the outer ends of the rolls, the arm It turns sharply forward and has the forwardly extending part it on which the rolls are mount th roll l6 h ving a fixed axial support on arm extension l4 and the roll i2 being mounted in a bracket toward the forward end of the extension I for move ment toward and from roll it about an axis 92 which is parallel with the axis of roll i2 and adjustable on its block mount into or out of parallelism with roll I!) by means of set screw H and clamping screws l3. 1

Referring to Fig. 2, the roll H1 is shownmount= ed on a sleeve 2! which in turn is rotatably a selvage is adapted to engage to cause swinging of the lever. In Fig. 3 lever 72 is shown pivoted at 16 on a part of arm extension [4, the pivot preferably including a ball bearing providing sensitivity of response of lever 12 to engagements by a selvage.

The lever arm having the V-notch 14 extends ene al y horizont l y at a plane below the piv I 6 of the lever, when the brake member 50 is engaged with brake ring 52, so that engagement of a downwardly travelling selvage in the. V-

notch .14 can swing the lever clockwise about its 7 pivot. The other and shorter arm 13 of the lever mounted on a spindle 22 whose outer end-is secured in arm extension It as by the set screw 24. A ballebearingzfi rotatably supports the inner end of sleeve 2;! on the inner end'oi spindle 22, it being secured by nut '23 on reduced ort on o t e p nd 7 and a bearing: t ably supports the outer end of the sleeve 24 on the spindle, this bearing preferably being an oilless bearing. Felt or the like-packing washers may beh d nenseeement with t e bear n 215.com a coil'sprl s 3 Ro l w ll, as shown is. made iii-three sections it. 38, and, 40;. S ction 4.0. ma consist. of a r laiy ly thick cylinder of; rubber cemented or otherw se ecu ed to, the inn r end of; l eve to rot tetherewith, Section .38 may consist of an oil-less bushing 42 freely rotatable on sleeve 2!, ands rubber cylinder 3.8 cemented or otherwise secured to bushing 62. The section 89 of roll It imilarly has its cylinder .36 of rubber cemented or otherwise secured to an oil-Jess bushing 44 which is. freely rotatable on sleeve 21. This bushing 44, however, has secured thereto a brake ring 46. having a friction surface 68 for co-action with a brake member 559 which is movable from. en.- gagement with .arbrake. ring 52 fixed on the outer nd of sleeve 2 to and through a neutral. position and-into. engagement with the brake ring .46

of roll section 36.

Brake member 50 is carried within a yoke 54 which ispivoted; at 56. (Figs. 1 and 4) on bracket 53 molesting forwardly from swinging arm M. Member 59 is mounted on the ends of oppositely disposed screws Ell, 63 in yoke 5 (Fig.2) so that its. braking surfaces continue parallel with the braking surfaces of rings at, 52 when yoke 54 A coil spring 64 tends always to maintain the brake member 50 in engagement with brake ring .52 so that the inner rollsection 40 will be in condition to impose a drag on a webW initially inserted between the rolls. while sections 35, 38. will be free runnine on sleeve-2.1.. One end of spring 54 is shown engaged withvscrew'fifl and its other end is loosely engaged with the headed end ofa screw 66 which extends through ear .68 on arm extension M", with a wing nut on the threaded end of the screw for adjusting the tension of the spring.

In. theoperation of my cloth guider, the brake member 5.0 is shifted to neutral position orinto enga ement with brake ring 156 by means of a bell crank lever 1.2 which is responsive to outward travel of a selvage between the rolls Ill, l2. e er zs own cons sts of two lever plates superimposed andrivetedtogether; the plates at their inner ends diverging, inthe embodiment of Figs! o vide a V-notch-"M ithin which ha generally vertical extent and its end portion is in position toengage the outer end of an adjustable threaded pin 18 which may be screwed into yoke 54 more or less and which can be locked in any adjusted position by lock nut 80. A stop pinBJ. may be provided for limiting outward movement of lever arm 13.

If a selvage departs outwardly along rollsi0, 12 from a predetermined course,v it engag s in the V-notch 14 and produces frictional drag-on V-notched end of the, bell crank lever- 12 which causes a clockwiseswinging of lever 1-12, considering the left ha/nd unit in 5, or a counters. c w se swi ng of lever 12,, c nsidering the right-hand unit in Fig. 5. This results; IiXOku 54 being swung inward about its-.pivotiii thfilieby' to move brake m mber 5, fr m eng gement with brake ring- 52 to a neutral position out-oftoonzhaot with b t ke 52- and 46, All sections of the tiltable unit is located outw rd; of its ni ot:

[6 so that g a ity nds to rotate. the l is-hand t c u t rl ckwise, and the right-hand unit: clockwise, as viewed Big. 5. A coil, spring resiliently opp s s this gravitational. tendency and may b adju t as to tens on, by wing; not

8.4 so. that the un t s approximately balanced henth rollsare; horizontal or nearly so. al.- though it may b desi b e. f r somework to. balance.- the rolls in; a pred termined.sli htly-tilted position. V

If. the s l age c ntinues-to moveloutward aiter h brak membe 50 has be nymoved: to. neutral".

p sition. the. incident frictional drag 'tiltsxle er 2 sti l furthe until. brake. member 25.0: moves into agement with rake ring '46 thereby to brake ollsec on and-apply a-drag to the, Web W- at hejselvase r ion thereof, to the left, of pivot. N5 of the unit (Figs. 1 and 3). This resultslin h W b tilting th un n he opposite direction about Pi t so hat the. rolls; art on the cloth w th nwardlyoronuisiveeficotuntil, the selva e: ov s a kto a, pred t rm ned normalzcourse.

0 1 112. similar'to roll I10; iszmade'in threersec-fl ns which. c -act with sections; 36-, 3B and-4n;

roll; however, is mounted on a bracket as V n which; the: spindle 8B: has-its outerzendi secured in any suitable manner, and the bracket 86: is

mounted with along bearing "8?! on. aspi-ndl'e- 92 whi h adiustably. supported at :the .outer' end. of anelevated oartpf-projection 1 14! of armtil d. A coil spring 94 has one end conneotediat. 95 to arm. Mend has its other enden'eaged-iaround hfirh fi dfid "end of a;.1screw 96-. which. extends through-an car '98; on. bracket-:8.6, with.a,- wing hut: J

smu h as; the dra mposed on the I00 on the threaded end of the screw for adjusting the tension of spring 94. Hence the spring 94 constantly resiliently urges roll I2 against roll It]. The roll sections of roll l2 may be similar to those of roll l0 excepting that all of the sections are freely rotatable, although if desired this roll also may be provided with a brake like that operative on roll Iii. However, any braking action on a section of roll H! acts to correspondingly slow down the co-acting section of roll l2 and ordinarily there is no need for separate braking of roll l2.

Adjustment for wear of the braking surfaces may be accomplished easily by screwing brake ring 52 inward on sleeve 2| a needed amount and screwing pin 18 outward to the left in Fig. 3 a corresponding amount.

Referring more particularly to Fig. 3, wherein bracket 86 is broken away and roll l2 removed, the unit is in position with the axis of the roll l0 horizontal, the spring 82 balancing the gravita tional tendency of the unit to turn about axis IS. The central portion of roll H3 also is broken away in this View to show the limits of tilting of the unit. Lug H52 on arm l4 engaging part M4 on base l8 limits tilting of the unit in one direction about its pivot It; and part 16 on arm l4 engaging part 108 on base l8 limits tilting of the unit in the opposite direction. These limits permit considerably more tilting in one direction than in the other because at times the inner ends of the rolls must be tilted substantially downward for exerting substantial lateral traction on the cloth, such as when a selvage is initially inserted between the inner ends of the rolls and must be carried outward between the rolls to attain a full spread of the cloth. This substantial downward tilt of the rolls naturally results when the selvage is initially engaged, due to the drag imposed thereon as a result of braking of the inner section 40 of roll 56. However, as soon as the selvage frictionally engages in the V-notch M of bell crank lever '52 and tilts it, the brake member 50 is shifted to release roll section 40 and spring 82 then acts to swing the unit back to or close to horizontal position. Actually the rolls normally would tilt slightly downward when a web of cloth is being guided through the device, and the opposite selvages will normally just engage the bell cranks enough to maintain the brake members 58 in neutral positions, until a departure of a selvage from its predetermined course causes a shifting of a brake member 50 until the selvage has returned to its proper course.

In Fig. 6 there is indicated a finger type of selvage engaging means on the brake actuating lever 12'. The spaced fingers H0, H2 extend in a diverging relation along the rolls H], l2 in a relation whereby, when a web engages between them, more and more friction is produced as the selvage moves laterally outward, as particularly described in United States Letters Patent No. 2,118,375, granted May 24, 1938, to Julien Dungler.

It should be understood that my invention resides in the provision for causing a drag on the cloth for tilting a roll unit in direction to correct a selvage deviation or to stop lateral movement of a selvage, in response to frictional drag of a selvage on the brake controlling means, and while I have shown one satisfactory manner of mounting the roll units and what I now consider to be a preferred form of braking means and control therefor responsive to lateral shifting of a selvage, the roll units may be otherwise tiltably mounted and various forms of brakes and controls may be utilized without departing from the spirit and scope of my invention so long as a braking means is responsive to frictional drag of a selvage resulting from a lateral outward movement of the selvage between the rolls Ill and i2.

I claim as my invention:

1. In a web guiding machine, a pivoted unit having a pair of coacting rolls for engaging opposite faces of a travelling web at a marginal region of the web, said rolls imposing a drag on the web whereby the web tends to tilt the rolls about the pivot of said unit, a brake movable into and out of braking relation to at least one of said rolls to vary the amount of drag imposed by the rolls on said web thereby to vary the degree of tilt of the rolls, and brake actuating means having a part in position for engagement by the web and responsive to frictional drag of the web thereon for actuating said brake.

'2. In a web guiding machine, a pivoted unit having a pair of coacting rolls for engaging opposite faces of a travelling web at a marginal region of the web, said rolls imposing a drag on the web whereby the web tends to tilt the rolls about the pivot of said unit, adjustable means yieldingly opposing tilting of said rolls in one direction by the web, a brake movable into and out of braking relation to at least one of said rolls to vary the amount of drag imposed by the rolls on said web thereby to vary the degree of tilt of the rolls, and brake actuating means having a part in position for engagement by the web and responsive to frictional drag of the web thereon for actuating said brake.

3. In a web guiding machine, a pivoted unit having a pair of coacting rolls for engaging opposite faces of a travelling web at a marginal region of the web, said rolls imposing a drag on the web whereby the web tends to tilt the rolls about the pivot of said unit, a coil spring adjustably tensioned between said unit and a relatively fixed support and resiliently opposing tilting of said rolls in one direction by the web, a brake movable into and out of braking relation to at least one of said rolls to vary the amount of drag imposed by the rolls on said web thereby to vary the degree of tilt of the rolls, and brake actuating means having a part in position for engagement by the Web and responsive to frictional drag of the web thereon for actuating said brake.

4. In a web guiding machine, a pivoted unit having a pair of coacting rolls for engaging opposite faces of a travelling web at a marginal region of the web, said rolls imposing a drag on the web whereby the web tends to tilt the rolls about the pivot of said unit, a brake movable into and out of braking relation to at least one of said rolls to vary the amount of drag imposed by the rolls on said web thereby to vary the degree of tilt of the rolls, and a brake actuating lever having one arm extending into position to be engaged by an edge region of the web as the said edge region of the web moves laterally outward between the rolls, whereby the lever is rocked varying amounts by frictional drag of the' web thereon.

5. In a web guiding machine, a pivoted unit having a pair of coacting rolls for engaging opposite faces of a travelling web at a marginal region thereof, said rolls each comprising a plurality of independently rotatable sections adapted to impose a drag on the web whereby the web tends to tilt the rolls about the pivot of said unit, a brake movable into and out of braking relation to at least one section of at least one of therolls to vary theamount' of drag imposed by the rolls on said webthereby to vary the degree of tilt of the rolls, and brake actuating means responsive to frictional drag of an edge region of th web thereon.

6. In a web guiding machine, a pivoted unit having a pair of coacting rolls for engaging opposite faces of a travelling web at a marginal region thereof, said rolls each comprising a plurality of independently rotatable sections adapted to impose a drag on the web whereby the web tends to tilt the rolls about the pivot of said unit, a brake movable into and out of braking relation to at least one section of at least one of the rolls to vary the amount of drag imposed by the rolls on said web thereby to vary the degree of tilt of the rolls, brake actuating means responsive to frictional drag of an edge'region of the web thereon, and means yieldingly urging said brake into braking relation toa section of one roll and operative to brake that section in absence of a brake actuating frictional drag of the web on said brake actuating means.

7. In a web guiding machine, a pivoted unit having a pair of coacting rolls for engaging opposite faces of a travelling web at a marginal region thereof, said rolls each comprising a plurality of independently rotatable sections adapted to impose a drag on the web whereby the web tends to tilt the rolls about the pivot of said unit, a brake movable into and out of braking relation to different sections of at least one of the rolls to vary the amount of drag imposed by said rolls on said web thereby to vary the degree of tiltof the rolls, said different brakable sections being on opposite sides of the pivot of said unit whereby the web tends to tilt the rolls in one direction about said pivot when one section of a roll is braked and in the opposite direction when the other section of a roll is braked, and brake. actuating means responsive to frictional drag of an edge region of the web thereon for shifting the brake from one to the other of said roll sections.

8. Mechanism for guiding a travelling Web, comprising a pair of pivotally mounted guide units operative on a travelling web at opposite marginal regions thereof, each said unit comprising a, pair of coacting guide rolls disposed generally transversely of the Web, and a pivoted frame rotatably supporting the rolls at their outer ends, the pivot of said frame having axial extent perpendicular to the plane of the web and being located in the common plane of the axes of said rolls and inward toward the center-line of travel of the web relative to the center of gravity of said unit, whereby gravity tends to rotate said unit in direction to tilt the inner ends of the rolls upwardly in parallelism with the web, adjustable resilient means counter-acting said rotational tendency due to gravity and effective to maintain the axes of said rolls in a predetermined plane of approximate balance in absence of substantial drag on the web applied by said rolls, said rolls each having a, plurality of rotatable sections of whichrone is outward and another inward of said pivot of the frame, means associated with at least one of said rolls for selectively braking different sections thereof, and means located for frictional engagement by an edge region of a web and yiel'd'ably responsive to frictional drag of the web thereon for shifting said braking means and altering the drag effect of said rolls on the web.

9. Mechanism forv guiding a travelling web.

comprising a pair of pivotally mounted guide units operative on a travelling web at opposite marginal regions thereof, each said unit comprising a pair of coacting guide rolls disposed generally transversely of the web, and a pivoted frame rotatably supporting the rolls at their outer ends, the pivot: ofsaid frame having axial ex tent perpendicular to the plane of the web and being located in the common plane of the axes of" said rolls and inward toward the center-line of'travel of the web relativeto the center of gravity of said unit whereby gravity tends to rotate said unit in direction to tilt the inner ends of the rolls upwardly in parallelism with the web, means acting on said pivoted frame and adjustable to apply thereto a force counter-acting gravity for approximately balancing the rolls in a predetermined position, means for braking at least one of said rolls, thereby to cause drag on the, travelling web and resulting tilting, of the rolls, and means in the path of outward travel of an edge of the web and yieldingly responsive to frictional drag of the web thereon for shifting said braking means and altering the drag effect of said rolls on the web.

l0. Mechanism for guiding a travelling web comprising a pair of pivotally mounted guide units operative on a travelling Web at opposite marginal regions thereof, each said unit comprising a pair of coacting guide rolls disposed generally transversely of the web and a pivoted frame rotatably supporting the rolls at their outer ends, the pivot of said frame having axial extent perpendicular to the plane of the web and being located in the common plane of the axes of said rolls and inward toward the center-line of travel of the web relative to the center of gravity of said unit whereby gravity tends to rotate said unit in direction to tilt the inner ends of the rolls upwardly in parallelism with the web, means acting on said pivoted frame and adjustable to apply thereto a force counter-acting gravity for approximately balancing the rolls in a predetermined position, means for braking, at least one of said rolls thereby to cause drag on the travelling web and resulting tilting of the rolls, and means in the path of outward travelv of an edge of the web and yiel'dingly responsive, to frictional drag of the Web thereon for shifting said braking means and altering the drag effect of said rolls on the web, and adjustable means for compensating for wear at the braking surfaces. 1 I

11. A web guiding mechanism comprising oppositely disposed pairs of coacting guide rolls for engaging opposite marginal regions of a travelling Web, mounting means for each pair of rolls, each said mounting means being pivotally supported for'movement in directions to tilt theaxes of its rolls. in. parallelism with the web, adjustable means yieldably holding each mounting means and its rolls with the axes of the rolls ap proximately at right angles to the center-line of travel of the web, means for braking at least one roll of each pair of rolls thereby to cause drag on the travelling web' and consequent tilting of the rolls, and means located for engagement by an edge region of the web and yieldingly respon sive to frictional drag of the web thereon for shifting, said braking means and effect of the rolls on the Web.

12. In a web guiding mechanism having tiltable pairs of rolls engaging opposite side margins of a travellin web, means for controlling the tilting of a saidpair of rolls comprising-a plural sec-,

tion construction of the rolls of which one see altering the drag.

tion of each roll projects to one side of the axis of tilting of the rolls and another section of each roll projects to the opposite side of the said axis, braking means selectively engageable with different sections of one of the rolls, and means responsive to frictional engagement of'an edge region of the web thereon for shifting said braking means and altering the drag effect of the rolls on the web.

13. In a web guiding mechanism having tiltable pairs of rolls engaging opposite side margins of a travelling web, means for controlling the tilting of a said pair of rolls comprising a plural section construction of the rolls of which one sec tion of each roll projects to one sided the axis of tilting of the rolls and another section of each roll projects to the opposite side of the said axis, braking means selectively engageable with different sections of one of the rolls and having an intervening neutral position in which it is disengaged from all roll sections, and means located for engagement by an edge region of a web and yieldable to shift said braking means in response to frictional drag of the web thereon, said braking means being resiliently urged into braking engagement with one of said roll sections, and said yieldable means being located relative to a predetermined course of travel of a said edge region of the web so that said yieldable means normally is held by said edge region of the web, on its normal course, in position maintaining said braking means in its said neutral position.

14. A web guiding mechanism having tiltable pairs of rolls engaging opposite side margins of a travelling web, each of said rolls comprising a plurality of rotatable sections and at least one roll of each pair having an inner end section fixed on the inner end of a rotatable sleeve extending throughout the length of the roll and having another section freely rotatable on said sleeve, said sleeve having a brake ring fixed thereon at its outer end and said freely rotatable section of roll having a similar but oppositely disposed brake ring fixed on the outer side thereof, a brake shiftable selectively into engagement with said brake rings and to a neutral position between said brake rings, and means responsive to frictional engagement of an edge region of the web therewith for shifting said brake.

15. A web guiding mechanism having tiltable pairs of rolls engaging opposite side margins of a travelling web, each of said rolls comprising a plurality of rotatable sections, braking means movable for engaging difierent sections of a said roll, means resiliently urging said braking means into engagement with one section of said roll, and a bell-crank lever having one arm engaging said braking means and its other arm formed at its end with a V-notch constituting an abutment in the path of outward movement of an edge of the web and yieldable to shift said braking means in response to frictional engagement therewith of a said edge of the web.

16. In a web guiding machine, a pivoted unit having a pair of coacting rolls for engaging opposite faces of a travelling web at a marginal region of the web, said rolls imposing a drag on the web whereby the web tends to tilt the rolls about the pivot of said unit, a brake movable into and out of braking relation to at least one of said rolls to vary the amount of drag imposed by the rolls on said web thereby to vary the degree of tilt of the rolls, and brake actuating means having a part in position for engagement by the web and responsive to engagement of the web therewith for actuating said brake.

17. In a web guiding machine, a pivoted unit having a pair of coacting rolls for engaging opposite faces of a travelling web at a marginal region of the web, said rolls imposing a drag on the web whereby the web tends to tilt the rolls about the pivot of said unit, a brake movable into and out of braking relation to at least one of said rolls to vary the amount of drag imposed by the rolls on said web thereby to vary the degree of tilt of the rolls, and brake actuating means having a part in position for engagement by the web and responsive to edgewise pressure of the web thereon for actuating said brake.

18. In a web guiding machine, a pivoted unit having a pair of coacting rolls for engaging opposite faces of a travelling web at a marginal region of the web, said rolls imposing a drag on the web whereby the web tends to tilt the rolls about the pivot of said unit, abrake movable into and out of braking relation to at least one of said rofis to vary the amount of drag imposed by the rolls on said web thereby to vary the degree of tilt of the rolls, and brake actuating means having an abutment in the path of outward lateral movement of an edge of the web and responsive to lateral pressure of an edge of the web thereon for actuating said brake.

- J OHN D. ROBERTSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Y Date 1,857,941 Corley et a1 May 10, 1932! 1,875,777 Tackaberry Sept. 6, 1932 1,919,291 Collidge July 25, 1933 2,096,087 Coolidge Oct. 19, 1937' 2,118,375 Dungler May 24, 1938 FOREIGN PATENTS Number Country Date 1,867 Great Britain 1883 343,059 France Dec. 2, 1905! 408,590 France Jan. 27, 1909 

